HOSPITALIZED. Liza Minnelli, 38, effervescent singer-actress; for treatment of alcohol and Valium problems; at the Betty Ford Center in Rancho Mirage, Calif. Minnelli's newly acknowledged difficulties evoke rueful comparisons with her mother, Judy Garland, who suffered from drug and alcohol addiction for much of her life.

DIED. James F. Fixx, 52, guru of the fitness generation who wrote two bestselling books explaining the mechanics and extolling the benefits of jogging, The Complete Book of Running (1977) and Jim Fixx's Second Book of Running (1980); of an apparent heart attack while jogging; in Hardwick, Vt.

DIED. George Low, 58, boldly imaginative, Vienna-born engineer who goaded and guided the manned space program with the National Aeronautics and Space Administration and its predecessors from 1949 to 1976; of cancer; in Troy, N.Y. It was Low who suggested, in a 1960 memo to President John Kennedy, that a man could be put on the moon by decade's end. After the disastrous January 1967 fire that killed three astronauts, NASA Deputy Director Low took charge of redesigning and rebuilding the Apollo craft; with 90-hour, detail-obsessed work weeks, he met his deadline when Apollo 11 reached the moon in July 1969. In 1976, Low became president of his alma mater, Rensselaer Polytechnic Institute. Seven weeks ago, his son David was named an astronaut.

DIED. Oqirhuyakt, 84, former Mongolian warlord and last lineal descendant of Genghis Khan, the 13th century Mongol military genius whose horse-borne hordes conquered China and menaced all of Central Asia; of cancer; in Huhehot, Inner Mongolia. Because of his hereditary status, his large following and his cooperation with the new regime in Peking after 1949, Oqirhuyakt (the single-name form is common for Mongolians) became a regional official. The ashes of Genghis' 32nd-generation descendant will rest in the tomb of his illustrious ancestors on the Ordos Plateau.

DIED. Karl Wolff, 84, storm-trooper general and Nazi military governor of Italy who negotiated the surrender of 1 million German and Italian troops to the Allies on May 2, 1945, six days before the Third Reich collapsed; after a long illness; in Rosenheim, Germany. Although he was chief adjutant to SS Commander Heinrich Himmler, Wolff after the war denied knowledge of Hitler's final solution and was not tried as a war criminal. In 1964, however, he became the highest-ranking Nazi officer to be tried in a West German court; he was sentenced to 15 years for being "continuously engaged and deeply entangled in guilt," notably for supplying the boxcars that shipped 300,000 Polish Jews to the gas ovens at Treblinka.